Effect of hydrogen concentration on the bolometric performance of sputtered a-SixGe1 − x:H films

Abstract In this work bolometric films of a-Si x Ge 1 − x :H (x = 0.82) with hydrogen concentrations of 0.47%, 0.85% and 1.28%, obtained by sputtering under different hydrogen pressures, were electrically characterized in order to maximize its bolometric performance. Results show that higher hydrogen concentrations will result in films with higher resistance, higher temperature coefficient of resistance, higher voltage responsivity and higher thermal time constant, however the voltage noise also increases making the detectivity of the deposited films remain relatively constant at different hydrogen concentrations. These results give the possibility to tune important bolometric parameters by changing the hydrogen concentration of the films, this possibility can be used to better match thin bolometric films to read-out integrated circuits, nanoantennas or other integrated optical devices.